1. Field of the Invention
The present invention generally relates to a powder container for containing powder such as toner and an image forming apparatus such as a copier, a printer, a facsimile machine, a plotter, or a multifunction machine capable of at least two of these functions that includes the powder container.
2. Description of the Background Art
In general, electrophotographic image forming apparatuses such as copiers, printers, facsimile machines, or multifunction machines including at least two of these functions include a development device to develop latent images formed on an image carrier. In addition, cylindrical toner containers (bottles) for containing toner, removably installable in main bodies of image forming apparatuses, are widely used.
For example, JP-2004-287404-A proposes a toner bottle that includes a bottle body having an opening on one side, a cap to cover the opening of the bottle body, and a spiral protrusion formed in an inner circumferential surface of the bottle body. As the bottle body rotates, the toner contained in the bottle body is transported along the spiral protrusion to the opening of the bottle body. The cap is retained in the main body in such a way as not to rotate as the bottle body rotates. The toner discharged from the bottle body is discharged outside the toner bottle through a toner outlet formed in the cap and supplied to a development device. The toner outlet is formed on the bottom of the cap so that the toner flows down under its own weight.
The cap includes a shutter to open and close the toner outlet. The shutter opens and closes the toner outlet in conjunction with installation of the toner bottle in the image forming apparatus.
The toner bottle proposed in the JP-2004-287404-A can alleviate leakage of toner in replacement of the toner bottle compared with the toner bottle without the cap because users need not touch the toner outlet owing to the shutter.
Additionally, in JP-2006-058698-A, the cap of the toner bottle includes a nozzle insertion portion into which a nozzle provided in the main body of the image forming apparatus is inserted. The shutter of the toner outlet blocks the nozzle insertion portion when the toner bottle is not installed in the image forming apparatus, to prevent leakage of toner.
Additionally, JP-2008-233667 proposes a toner container in which the shutter to close the toner outlet is movable horizontally, which is identical to a direction in which the toner container is slidingly installed in the apparatus.
Those toner containers typically include discrimination protrusions projecting from outer circumferential surfaces of the toner containers. The shape or arrangement of the discrimination protrusions is unique to each color of toner, and insertion openings formed in the image forming apparatus have a shape that fits only the discrimination protrusion of the toner container for the corresponding color. Such an arrangement ensures that a toner container of the wrong color is prevented from being inserted set in a container mount for specific color in the apparatus.
In particular, in the arrangement in which the toner container is horizontally inserted in the image forming apparatus as in JP-2008-233667, it is important to prevent the toner container of wrong color from being set in the container mount. However, when the toner container of wrong color is inserted, depending on the arrangement of the discrimination protrusions, it is possible that opening the toner outlet of the toner container is already started by the time the discrimination protrusion hits the insertion opening.
Moreover, in JP-2008-233667-A, when the toner container of the wrong color is inserted, it is possible that the shutter jolts due to some reason, thus opening the toner outlet unintentionally, because the direction in which the shutter moves parallels the installation direction of the toner container. As a result, the toner of the wrong color leaks out and onto the container mount.